Hypodermic and other syringes



April 25, 1939. A. c. M KAY HYPODERMIC AND OTHER SYRINGES FiledDec.

w Won/v7 Patented Apr. 25, 1939 HYPOD'ERMIC AND Angus Conrad McKay,

Territory,

Application 1 Claim.

This invention relates to hypodermic and the like syringes, used for inoculating, drenching, blood transfusions, and other similar purposes, and of the kind wherein measured doses of liquid medicine are required to be administered.

Syringes of the above. type are well known and consist broadly of a cylindrical barrel or sheath of metal; a barrel liner or glass within a metal barrel or sheath; suitable caps for the ends of the barrel; means for operating a piston in the barrel and means for admitting the liquid to and discharging it from the barrel and means for adjusting the stroke of the piston with a view to regulating the amount of liquid discharged on each stroke of the piston.

An object of the present invention is to provide improved adjustable means whereby the amount of liquid discharged from the barrel or cylinder of the syringe at each outward stroke of the piston may be regulated at will.

The invention consists of a hypodermic or like syringe preferably having a graduated barrel of glass or other suitable transparent material, which can be fitted into a protecting sheath, provided with a cap of metal or other suitable material at each end, the sheath being so designed as to permit visibility of the contents of the glass barrel. This metal sheath may be fitted with a fixed or adjustable grip or hand piece suitable and convenient for the hand of the operator.

A piston or plunger made of metal or other suitable material is accurately fitted into the barrel. The piston contains an inlet valve such as a ball valve held on its seat by a spring. From this inlet valve a channel is constructed to communicate with the interior of the barrel to allow the fluid to pass into the barrel of the syringe. The piston is connected to a hollow piston rod which may be graduated, and through which the fluid is admitted.

An auxiliary hollow piston rod, sleeve, or collar, which may be split longitudinally, is concentrically mounted about the hollow piston rod, said auxiliary hollow piston rod preferably extending through, and outwardly from, the inner metal cap of the sheath.

An annular collar, which may be integral with the auxiliary hollow piston rod, bears on the inner face of the inner metal cap and serves as a stop for the piston rod when drawn back to its normal position automatically under the influence of a spring such action charging the barrel in readiness for the next injection or discharge stroke.

The movable handpiece of the device, by which the piston is actuated, preferably is detachably OTHER SYRINGES Canberra, Federal Capital Australia December 6, 1937, Serial No. 178,413 n Australia December '7, 1936 secured to the split portion of piston rod by means which contract the said split portion onto the hollow piston rod proper, thus securing the two together. Other means however,

may be provided for adjustably securing the annular collar or sleeve to the hollow piston rod.

The hollow piston rod extends beyond the auxiliary piston rod or collar to form a terminal onto which is connected flexible tubing or other device for delivering fluids from a suitable reservoir; the reservoir in some cases may be directly connected to the said piston rod.

The end of the barrel has a metal plug fitted thereto which is channelled to hold an outlet valve which may be similar to the inlet valve previously described, except that it enables the contents of the syringe to be discharged through the outlet channel which is continued through the outer end cap into a nipple screwed or otherwise fitted into the cap, and designed to take the hypodermic needle or drenching nozzle.

In order that the invention may be more readily understood and carried into practical effect, reference will now be made to the drawing, which illustrates one form of the invention, wherein:-

Figure 1 is an elevation of the syringe while Figure 2 is a longitudinal cross section of Figure 1.

Referring to the drawing, the protecting sheath or barrel 3 is preferably of metal, but may be of any other suitable material, and encloses a barrel 4 of glass or other suitable transparent material, and which is graduated to indicate the amount of fluid constituting a charge or dose.

The barrel 3 is fitted with a screw cap 5 of metal which is designed to permit of visibility of the contents of the glass barrel 4 while a fixed or adjustable grip 6 of metal is provided on the barrel 3 in a convenient position for the hand of the operator.

A piston or plunger 1 of metal or other suitable material is accurately fitted into the glass barrel 4 and carries an inlet valve consisting of a ball 8 and a spring 9, said ball 8 fitting accurately into a prepared seat It! in the piston or plunger 1.

From this inlet valve in the piston 1 a channel H is constructed to communicate with the interior of the glass barrel 4 thus allowing the fluid or other substance to pass therethrough into the said glass barrel 4 of the syringe.

Fitted to the top of the piston or plunger 1 is a hollow piston rod l2 which extends through the metal screw cap 5 on the barrel 3 of the syringe. The hollow piston rod l2 is preferably graduated and mounted concentrically thereon is an auxiliary hollow piston rod l3 also extending through the auxiliary hollow the cap 5, said auxiliary hollow piston rod l3 being split longitudinally at l4 through half or more than half its length.

The auxiliary hollow piston rod l3 has an annular collar l5 at the inner extremity thereof bearing against the inner face of the cap 5 and serving as a stop for the hollow piston rod l2 when drawn back to its normal position automatically under the infiuenceof a spring l6 fitted around the auxiliary hollow piston rod I3 and which charges the glass barrel 4 in readiness for a subsequent injection or discharge.

A movable handpiece ll adapted to actuate the v piston 1 through members l2 and I3 is attached to the auxiliary hollow piston rod l3 for instance by a suitable bolt or stud l8.

This bolt or stud l8 when screwed down tightly, contracts the split portion M of the auxiliary hollow piston rod I3 and clamps the said auxiliary hollow piston rod l3 to the hollow piston rod l2.

The hollow piston rod'l2 is prolonged to form a terminal!!! ontowhich is connected flexible tubing (not shown) or any other suitable device for delivering fluids from a reservoir.

Fitted into the end of the metal barrel 3 is a plug 20 channelled to hold an outlet valve 2| similar to the inlet valve 8; this valve enables the contents of the syringe to be emitted through an outlet channel 22 which is formed in a hollow projection or nipple 23 adapted to receive a hypo-.

dermic needle 24 or drenching nozzle as the case may be.

When it is desired to regulate the amount of dosage in the glass barrel 4 the adjusting bolt I8 is slackened relieving the pressure of the split portion M of the auxiliary hollow piston rod l3 on the hollow piston rod l2 with the result that the relative position of the piston rod and the auxiliary rod may be varied, and the piston I adjusted to any position in the glass barrel 4 according to the requirements of the operator.

I claim:

A hypodermic syringe and drencher comprising a barrel of glass or other suitable material, a metal sheath housing the barrel, a piston in the barrel having an inlet valve, said barrel also having a discharge valve, a hollow piston rod attached to the piston and through which fluid is fed to the barrel, and tubular means concentric with the piston rod for determining the stroke of the piston, said tubular means having a collar at one end for engagement with an end cap disposed on the said sheath, the other end of the tubular means being split longitudinally and having means thereon for adjustably securing together the sleeve and the hollow piston rod, said split end of the hollow means having a handle secured thereto said handle serving to clamp the tubular means to the hollow piston rod.

ANGUS CONRAD MCKAY. 

